Explosive.



UNITED STATES PAT T oEEioE.

FREDERICK GEOFFREYLEES JOHNSON, OF CHELSEA, LONDON, ENGLAND, ASSIGNOR TO PALMER-EERCHLORAIE POWDER COMPANY OF CANADA LIMITED, OF MONTREAL,

'Patented Aug. 20, 1918.

CANADA.

EXPLOSIVE.

1,276,537. Specification of Letters Patent. No Drawing.

To all whom it may concern e it known that I, FREDERICK GEOFFREY- LEEs JoHNsoN, a subject of the Kin of Great Britain, residing at 28 Elm ark road, Chelsea, in the county of London, England, have invented certain new and useful Improvements in Explosives, of which the following is a specification.

This invention relates to an explosive of suitable for use in shells, bombs, mines and the like, and for other purposes in which a high explosive is required.

According to this invention the explosive consists .essentially of ammonium perchlorate or a mixture of ammonium and potassium perchlorates, amounting to about five-sixths of the total weight, with some ignitible metal powder, such as zinc or aluminum, and resin, some mineral oil, vaseline or paraflin wax-being associated with the resin.

In preparing the explosive the perchlorate type,

sieve of 60 or higher mesh. The resin may be dissolved in a suitable solvent, such as benzole, Wood spirit, wood naphtha or the like, an approximately saturated solution being preferred and the solution (after straining) and the perchlorate are intimately mixed together in.any suitable type of mixing machine, after which the solvent is evaporated, leaving the perchlorate grains covered with 'a thin protecting layer of resin, or the resin may be dissolved in the mineral oil. Each grain is thus waterproofed.

A typical composition useful for most military purposes and especially for shells is made with about the follow-mg proportions of the ingredients Ammonium perchlorate, 84 per cent; resin, 5 per cent. oil (in which the resin may be dissolved) 6 per cent.; zinc'or aluminium powder 5 per cent.

For mines or torpedoes a somewhat more sensitive explosive may be employed con-' taining, say, 2 per cent. more perchlorate perchlorate is finely ground and should pass through a.

Application filed September 21, 1916. Serial No. 121,371.

and 2 per cent. less oil. Other variations ofthe resin and oil proportions may be made. As already mentioned part of the ammonium perchlorate may be replaced by potassium perchlorate where a somewhat lower grade explosive with greater insensitiveness is required. A mixture with about 40 per cent. potassium perchlorate and 44 per cent. ammonium perchlorate gives a good result but 10, 20, 30 or per cent. of the potassium salt may be used, the relation between the two salts depending on the circumstances of use and the relative cost of the ingredients.

The addition of the oil or wax to the resin renders the whole composition more plastic under pressure, this property being especially serviceable where the explosive has to be stemmed into the shells or other containers. In explosives intended for use in bombs, mines and the like and for blasting charges, where there is no risk of severe form, but where a reduction of sensitiveness is desired, as in charges for shells, the resin scribed. The explosive can be detonated efficiency without the use of a fulminate or ployed with high explosives.

e by Letters Patent of the United States is alkaline perchlorate amounting to about fivesixths by'weight of the total mass, and powder constituting the remainder of the composition.

about 84 per cent. of alkaline perchlorate and of about 16 per cent. of resin, mineral proportions.

In witness whereof, I

shook the resin may be mixed in in powdered should be added insolution as above deother detonator of the type commonly cmat I claim and desire to secu explosive composition consisting of resin, mineral oiland an ignitible metal An explosive composition consisting of oil and zinc powder in approximately equal signature.

herewith aflix my FREDERICK GEOFFREY LEl'lS JOHNSON. 

